Sun Oracle 4540 - Phaser Copystation, Service Manual, Page: 153 / 264

Chapter 3 Maintaining the Sun Fire X4500 and X4540 Servers 3-33
3. Use the operating system or management software to take the disk drive offline
before you replace it. Not doing so could cause data loss or unexpected error
messages.
Once the drive has been taken off line, the left (blue) LED should turn on. This
means the drive is ready to be removed and service action is allowed.
Caution – Pulling a drive that has that has not been prepared for removal can cause
a loss of the drive cell memory map or loss of data in its in/out buffers.
Note – If you are using the operating system command line, note that disks in the
enclosure are typically identified in sequential order. Although the enclosure contains
only 48 disks, your operating system may see a list of 51 devices; if this is the case,
the first 4 addresses (0-3) represent the enclosure's four SAS expanders, the other 48
addresses (4-51) represent the 48 drives.